The instant invention is directed to a detent joint, primarily for use with external mirrors of vehicles, but also with any external mirror which may require such a detent joint.
External mirrors of vehicles are generally fastened to the vehicle by means of one or several brackets.
Preferably swivel joints are employed to make it possible to pivot the mirror from the original position in which the mirror is set, essentially perpendicular to the side of the vehicle into a second position, in which the mirror stands essentially parallel to the side of the vehicle. This arrangement makes it a possibility to fold this mirror into the side of the vehicle during transport and parking decreasing its overall width or to fold the mirror back against the side in order to avoid, or at least diminish damage to the mirror upon collision with an obstacle as the case may be.
Advantageously, the swivel joints are designed in the nature of the detent joints, which engage the second position for at least the above-described reason—that means they oppose the clearly heightened resistance of the torque around the axis of rotation. Aside from that, still other detent positions can be made available which enable different basic positions while keeping the possibility for adjustments of the mirror pane relative to the mirror. In order to adjust the mirror's surface relative to his sitting position, the driver can initially bring the entire mirror to a suitable basic position and then adjust the angle of the mirror pane exactly for his position.
A similar arrangement is taught by EP 1 092 589. In this arrangement a first hinge piece, on which the mirror can be secured, as well as a second hinge piece for the attachment to the vehicle are provided. Both hinge pieces are joined together in such a way as to be rotated about a rod. This motion is accomplished by two arms of the first hinge piece which cooperate with second two arms of the second hinge piece, and a cylindrical part set in between. The cylindrical part is fixed to the second hinge piece by means of two clamp blocks that partially encompass its circumference. The cylindrical part has several evenly-spaced external notches on its circumference on the side turned toward the first hinge piece. A complementarily formed detent element is pushed back and set in the first hinge piece in the radial direction and is spring-forced in this direction, so that in each case one of the notches of the cylindrical part is engaged allowing the hinge pieces relative movement in the radial direction.
If the first hinge piece is turned around the second, the detent element is moved out of a notch against the resistance of the spring and, by the strength of the spring, is pushed into the next notch as soon as it lies directly across from the detent element, thus resulting in different detent positions. Because the cylindrical part is pivoted to the second hinge piece in different positions, the detent positions can be secured arbitrarily as regards the second hinge piece.
The primary drawback to this arrangement is that the detent joint consists of many pieces which results in costly manufacturing and unwanted tolerance of the joint as a result of the tolerance chains. Also, the stroke direction of the detent element must always lead radially through the axis of rotation, so that no disequalibriated torque is induced. This line of engagement of rotation of the axis-detent engagement-stroke of the detent element requires a relatively large space in the direction of the stroke. The larger lever arm controls the hinged position of the external mirrors which results in destabilization of the detent joint.
It is an object of the instant invention to provide a detent joint which is tolerance-free as much as possible and by which the rotation axis may be arranged outside of the line of engagement. A further object of the instant invention is to make an external mirror with a tolerance-free detent joint and in which the axis of rotation may be placed outside the line of engagement.